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Methods in Molecular Biology (Clifton,... 2016The Wilms' tumor suppressor gene Wt1 is highly conserved among vertebrates. In contrast to mammals, most fish species possess two wt1 paralogs that have been named wt1a... (Review)
Review
The Wilms' tumor suppressor gene Wt1 is highly conserved among vertebrates. In contrast to mammals, most fish species possess two wt1 paralogs that have been named wt1a and wt1b. Concerning wt1 in fish, most work so far has been done using zebrafish, focusing on the embryonic kidney, the pronephros. In this chapter we will describe the structure and development of the pronephros as well as the role that the wt1 genes play in the embryonic zebrafish kidney. We also discuss Wt1 target genes and describe the potential function of the Wt1 proteins in the adult kidney. Finally we will summarize data on the role of Wt1 outside of the kidney.
Topics: Animals; Embryo, Nonmammalian; Gene Expression Regulation, Developmental; Heart; Kidney; Myocardium; Pronephros; WT1 Proteins; Zebrafish; Zebrafish Proteins
PubMed: 27417964
DOI: 10.1007/978-1-4939-4023-3_10 -
Developmental Biology Dec 2014The zebrafish pronephros provides an excellent in vivo system to study the mechanisms of vertebrate nephron development. When and how renal progenitors in the zebrafish...
The zebrafish pronephros provides an excellent in vivo system to study the mechanisms of vertebrate nephron development. When and how renal progenitors in the zebrafish embryo undergo tubulogenesis to form nephrons is poorly understood, but is known to involve a mesenchymal to epithelial transition (MET) and the acquisition of polarity. Here, we determined the precise timing of these events in pronephros tubulogenesis. As the ternary polarity complex is an essential regulator of epithelial cell polarity across tissues, we performed gene knockdown studies to assess the roles of the related factors atypical protein kinase C iota and zeta (prkcι, prkcζ). We found that prkcι and prkcζ serve partially redundant functions to establish pronephros tubule epithelium polarity. Further, the loss of prkcι or the combined knockdown of prkcι/ζ disrupted proximal tubule morphogenesis and podocyte migration due to cardiac defects that prevented normal fluid flow to the kidney. Surprisingly, tubule cells in prkcι/ζ morphants displayed ectopic expression of the transcription factor pax2a and the podocyte-associated genes wt1a, wt1b, and podxl, suggesting that prkcι/ζ are needed to maintain renal epithelial identity. Knockdown of genes essential for cardiac contractility and vascular flow to the kidney, such as tnnt2a, or elimination of pronephros fluid output through knockdown of the intraflagellar transport gene ift88, was not associated with ectopic pronephros gene expression, thus suggesting a unique role for prkcι/ζ in maintaining tubule epithelial identity separate from the consequence of disruptions to renal fluid flow. Interestingly, knockdown of pax2a, but not wt1a, was sufficient to rescue ectopic tubule gene expression in prkcι/ζ morphants. These data suggest a model in which the redundant activities of prkcι and prkcζ are essential to establish tubule epithelial polarity and also serve to maintain proper epithelial cell type identity in the tubule by inhibiting pax2a expression. These studies provide a valuable foundation for further analysis of MET during nephrogenesis, and have implications for understanding the pathways that affect nephron epithelial cells during kidney disease and regeneration.
Topics: Animals; Cell Polarity; DNA Primers; Dextrans; Epithelial Cells; Fluorescent Antibody Technique; Gene Expression Regulation, Developmental; In Situ Hybridization; Isoenzymes; Microscopy, Confocal; Organogenesis; PAX2 Transcription Factor; Pronephros; Protein Kinase C; Zebrafish; Zebrafish Proteins
PubMed: 25446529
DOI: 10.1016/j.ydbio.2014.08.038 -
Scientific Reports Nov 2023The transcription factor Six2 plays a crucial role in maintaining self-renewing nephron progenitor cap mesenchyme (CM) during metanephric kidney development. In mouse...
The transcription factor Six2 plays a crucial role in maintaining self-renewing nephron progenitor cap mesenchyme (CM) during metanephric kidney development. In mouse and human, expression at single-cell resolution has detected Six2 in cells as they leave the CM pool and differentiate. The role Six2 may play in these cells as they differentiate remains unknown. Here, we took advantage of the zebrafish pronephric kidney which forms directly from intermediate mesoderm to test six2b function during pronephric tubule development and differentiation. Expression of six2b during early zebrafish development was consistent with a role in pronephros formation. Using morpholino knock-down and CRISPR/Cas9 mutagenesis, we show a functional role for six2b in the development of proximal elements of the pronephros. By 48 h post-fertilization, six2b morphants and mutants showed disrupted pronephric tubule morphogenesis. We observed a lower-than-expected frequency of phenotypes in six2b stable genetic mutants suggesting compensation. Supporting this, we detected increased expression of six2a in six2b stable mutant embryos. To further confirm six2b function, F crispant embryos were analyzed and displayed similar phenotypes as morphants and stable mutants. Together our data suggests a conserved role for Six2 during nephrogenesis and a role in the morphogenesis of the proximal tubule.
Topics: Animals; Humans; Mice; Morphogenesis; Nephrons; Pronephros; Zebrafish; Zebrafish Proteins
PubMed: 37952044
DOI: 10.1038/s41598-023-47046-3 -
Journal of Medicinal Chemistry Jan 2022NIMA-related kinase 1 (Nek1) has lately garnered attention for its widespread function in ciliogenesis, apoptosis, and the DNA-damage response. Despite its involvement...
NIMA-related kinase 1 (Nek1) has lately garnered attention for its widespread function in ciliogenesis, apoptosis, and the DNA-damage response. Despite its involvement in various diseases and its potential as a cancer drug target, no directed medicinal chemistry efforts toward inhibitors against this dark kinase are published. Here, we report the structure-guided design of a potent small-molecule Nek1 inhibitor, starting from a scaffold identified by kinase cross-screening analysis. Seven lead compounds were identified and evaluated for their inhibitory activity. The top compound, , was further profiled for efficacy, toxicity, and bioavailability in a zebrafish polycystic kidney disease model. Administration of caused the expansion of fluorescence-labeled proximal convoluted tubules, supporting our hypothesis that Nek1-inhibition causes cystic kidneys in zebrafish embryos. Compound displayed insignificant inhibition in 48 of 50 kinases in a selectivity test panel. The findings provide a powerful tool to further elucidate the function and pharmacology of this neglected kinase.
Topics: Animals; Drug Design; Embryo, Nonmammalian; NIMA-Related Kinase 1; Polycystic Kidney Diseases; Pronephros; Protein Kinase Inhibitors; Zebrafish
PubMed: 35081715
DOI: 10.1021/acs.jmedchem.0c02118 -
Developmental Dynamics : An Official... Dec 2015Development of the pronephros in Xenopus laevis is largely dependent on retinoic acid signaling at the time of kidney field specification with the simultaneous...
BACKGROUND
Development of the pronephros in Xenopus laevis is largely dependent on retinoic acid signaling at the time of kidney field specification with the simultaneous occurrence of a necessary calcium signaling. At the crossroads of these two signaling pathways, we studied the role of Hspa9 (heat shock 70 kDa protein 9) encoding a mitochondrial chaperone in pronephros development.
RESULTS
We first showed that Hspa9 is highly expressed in the pronephros territory and elongating nephric duct. We then observed that upon reduced retinoic acid signaling hspa9 expression was reduced as pax8 and pax2. Overexpression of hspa9 enlarged the pax8 positive pronephros territory, leading to a larger pronephric tubule. Loss of function of hspa9 in the kidney field using morpholino approach severely reduced pax8 expression and pronephros formation. Phenotypic rescue was achieved by co-injection of the full-length murine Hspa9 mRNA. However, no rescue was observed when Hspa9 mRNA lacking the mitochondrial-targeting sequence was injected, as this truncated form is able to interfere with pronephros formation when injected solely.
CONCLUSIONS
Hspa9 is an important mediator for pronephros development through modulation of pax8. Mitochondrial functions of hspa9 are likely to be involved in specification of pronephric cell fate.
Topics: Animals; Gene Expression Regulation, Developmental; HSP70 Heat-Shock Proteins; Mitochondrial Proteins; Paired Box Transcription Factors; Pronephros; Signal Transduction; Tretinoin; Xenopus Proteins; Xenopus laevis
PubMed: 26335666
DOI: 10.1002/dvdy.24344 -
The International Journal of... 2016Pdzrn3, a multidomain protein with E3-ubiquitin ligase activity, has been reported to play a role in myoblast and osteoblast differentiation and, more recently, in...
Pdzrn3, a multidomain protein with E3-ubiquitin ligase activity, has been reported to play a role in myoblast and osteoblast differentiation and, more recently, in neuronal and endothelial cell development. The expression of the pdzrn3 gene is developmentally regulated in various vertebrate tissues, including muscular, neural and vascular system. Little is known about its expression during kidney development, although genetic polymorphisms and alterations around the human pdzrn3 chromosomal region have been found to be associated with renal cell carcinomas and other kidney diseases. We investigated the pdzrn3 spatio-temporal expression pattern in Xenopus laevis embryos by in situ hybridization. We focused our study on the development of the pronephros, which is the embryonic amphibian kidney, functionally similar to the most primitive nephric structures of human kidney. To explore the role of pdzrn3 during renal morphogenesis, we performed loss-of-function experiments, through antisense morpholino injections and analysed the morphants using specific pronephric markers. Dynamic pdzrn3 expression was observed in embryonic tissues, such as somites, brain, eye, blood islands, heart, liver and pronephros. Loss of function experiments resulted in specific alterations of pronephros development. In particular, at early stages, pdzrn3 depletion was associated with a reduction of the pronephros anlagen and later, with perturbations of the tubulogenesis, including deformation of the proximal tubules. Rescue experiments, in which mRNA of the zebrafish pdzrn3 orthologue was injected together with the morpholino, allowed recovery of the kidney phenotypes. These results underline the importance of pdzrn3 expression for correct nephrogenesis.
Topics: Animals; Carrier Proteins; Embryo, Nonmammalian; Gene Expression Regulation, Developmental; Genetic Complementation Test; Humans; In Situ Hybridization; Morphogenesis; Mutation; Pronephros; RING Finger Domains; RNA, Messenger; Xenopus Proteins; Xenopus laevis; Zebrafish Proteins
PubMed: 26934292
DOI: 10.1387/ijdb.150381ld -
Journal of Developmental Biology Oct 2022The Wilms' tumor suppressor gene, , encodes a zinc finger-containing transcription factor that binds to a GC-rich motif and regulates the transcription of target genes....
The Wilms' tumor suppressor gene, , encodes a zinc finger-containing transcription factor that binds to a GC-rich motif and regulates the transcription of target genes. was first identified as a tumor suppressor gene in Wilms' tumor, a pediatric kidney tumor, and has been implicated in normal kidney development. The WT1 protein has transcriptional activation and repression domains and acts as a transcriptional activator or repressor, depending on the target gene and context. In , an ortholog of has been isolated and shown to be expressed in the developing embryonic pronephros. To investigate the role of in pronephros development in embryos, we mutated by CRISPR/Cas9 and found that the expression of pronephros marker genes was reduced. In reporter assays in which known WT1 binding sequences were placed upstream of the gene, WT1 activated transcription of the gene. The injection of wild-type or artificially altered transcriptional activity of mRNA disrupted the expression of pronephros marker genes in the embryos. These results suggest that the appropriate amounts and activity of WT1 protein are required for normal pronephros development in embryos.
PubMed: 36412640
DOI: 10.3390/jdb10040046 -
Scientific Reports Jul 2022Thiosulfate sulfurtransferase (TST, EC 2.8.1.1), also known as Rhodanese, was initially discovered as a cyanide detoxification enzyme. However, it was recently also...
Thiosulfate sulfurtransferase (TST, EC 2.8.1.1), also known as Rhodanese, was initially discovered as a cyanide detoxification enzyme. However, it was recently also found to be a genetic predictor of resistance to obesity-related type 2 diabetes. Diabetes type 2 is characterized by progressive loss of adequate β-cell insulin secretion and onset of insulin resistance with increased insulin demand, which contributes to the development of hyperglycemia. Diabetic complications have been replicated in adult hyperglycemic zebrafish, including retinopathy, nephropathy, impaired wound healing, metabolic memory, and sensory axonal degeneration. Pancreatic and duodenal homeobox 1 (Pdx1) is a key component in pancreas development and mature beta cell function and survival. Pdx1 knockdown or knockout in zebrafish induces hyperglycemia and is accompanied by organ alterations similar to clinical diabetic retinopathy and diabetic nephropathy. Here we show that pdx1-knockdown zebrafish embryos and larvae survived after incubation with thiosulfate and no obvious morphological alterations were observed. Importantly, incubation with hTST and thiosulfate rescued the hyperglycemic phenotype in pdx1-knockdown zebrafish pronephros. Activation of the mitochondrial TST pathway might be a promising option for therapeutic intervention in diabetes and its organ complications.
Topics: Animals; Diabetes Mellitus, Type 2; Hyperglycemia; Models, Theoretical; Pronephros; Thiosulfate Sulfurtransferase; Thiosulfates; Zebrafish
PubMed: 35840638
DOI: 10.1038/s41598-022-16320-1 -
Frontiers in Immunology 2021In mammals, Interleukin-17 cytokine family plays critical roles in both acute and chronic inflammatory responses. In fish species, three Interleukin-17A/F (IL-17A/F)...
In mammals, Interleukin-17 cytokine family plays critical roles in both acute and chronic inflammatory responses. In fish species, three Interleukin-17A/F (IL-17A/F) genes have been identified to be homologous to mammalian IL-17A and IL-17F, but little is known about their functional activity. In this study, _IL-17A/F1, 2 and 3 genes were cloned from yellow catfish () and they differed in protein structure and exon length, implying that they may have divergent bioactivity. Real-time quantitative PCR analyses revealed that three _IL-17A/F genes were highly expressed in blood and mucosal tissues (skin+mucus and gill) from healthy adult fish. The mRNA expressions of _IL-17A/F1, 2 and 3 genes were significantly up-regulated in the gill, skin+mucus, head kidney and spleen after challenge with and in the isolated peripheral blood leucocytes (PBLs) of yellow catfish after stimulation with phytohaemagglutinin (PHA), lipopolysaccharides (LPS), peptidoglycan (PGN) and polyinosinic-polycytidylic acid (Poly I:C). These results indicate that _IL-17A/F1, 2 and 3 genes may play a vital role in the regulation of immune against pathogens. Additionally, the recombinant (r) _IL-17A/F1, 2 and 3 proteins significantly induced the mRNA expressions of proinflammatory cytokines, chemokines and antibacterial peptides genes, and the r_IL-17A/F 2 and 3 proteins promoted phagocytosis of PBLs more powerfully than the r_IL-17A/F1. Furthermore, the r_IL-17A/F1, 2 and 3 proteins might activate the NF-κB and MAPK signal pathways by IL-17RA, ACT1, TRAF6, TRAF2, TRAF5 and TAK1, indicating that the three _IL-17A/F proteins may play different roles in promoting inflammatory response.
Topics: Animals; Catfishes; Fish Proteins; Head Kidney; Interleukin-17; Leukocytes; Lipopolysaccharides; Peptidoglycan; Phytohemagglutinins; Poly I-C; Spleen
PubMed: 34267744
DOI: 10.3389/fimmu.2021.626895 -
Developmental and Comparative Immunology Feb 2021Interleukin (IL) -2, a member of the four α-helical cytokine family, has broad regulatory roles in mediating vertebrate immune response. In mammals, IL-2 and IL-15...
Interleukin (IL) -2, a member of the four α-helical cytokine family, has broad regulatory roles in mediating vertebrate immune response. In mammals, IL-2 and IL-15 share a common evolutionary origin and possess overlapping but distinct functions. IL-2 and IL-15 bind to distinct private receptors for signaling. However, fish appear to possess a single IL-15Rα like gene whilst lack additional gene(s) coding for IL-2Rα. Whether the IL-2 and IL-15 interact with the same receptor in fish and how their functions and receptors have evolved are not fully understood. In this study, homologues of IL-2 and IL-2/15Rα were sequenced from a teleost species, grass carp (Ctenopharyngodon idella), and the crystal structure of IL-2 was determined. The grass carp IL-2 (termed CiIL-2) displayed a classical cytokine structure consisting of four helical bundles which shares significant similarity with human IL-15. The key amino acids involved in the interface interaction of IL-2/15 and their receptors are well conserved. The CiIL-2 has been shown to bind the IL-2/15Rα like homologue with an affinity of 2.45 nM, supporting the notion that fish IL-2 and IL-15 may share a single common private receptor for exerting functions. Syntenic analysis suggests that the IL-2Rα of tetrapods has evolved from an IL-15Rα like homologue, in which a second sushi domain (D2) in the extracellular region has been duplicated to facilitate the specific interaction with IL-2. The CiIL-2 was predominantly expressed in lymphocyte-rich tissues such as the spleen, kidney and thymus, and could be induced by PHA and IL-21. In vivo challenge with grass carp reovirus and Flavobacterium columnare also resulted in upregulation of CiIL-2 expression. The recombinant CiIL-2 was shown to activate expression of STAT5b, IL-1β, IL-22 and IFN-γ, and to promote the proliferation of the primary cell cultures from head kidney leucocytes. Our results shed lights into the co-evolution of IL-2 and its private receptor, and the functional divergence of IL-2 and IL-15 during evolution.
Topics: Animals; Carps; Cells, Cultured; Fish Diseases; Fish Proteins; Flavobacterium; Head Kidney; Interleukin-15; Interleukin-15 Receptor alpha Subunit; Interleukin-2; Leukocytes; Primary Cell Culture
PubMed: 33065202
DOI: 10.1016/j.dci.2020.103895